1. Field of the Invention
The invention relates to a bucket wheel equipped with a single-wall conical supporting body that is constructed as an inner shell and is rotatably mounted on the bucket wheel axis. The invention also relates to a device cooperating with the supporting body for accommodating the buckets at the outer circumference of the bucket wheel.
2. Description of the Related Art
German Patent 2,314,241 discloses a non-cellular bucket wheel which has a conically configured supporting body that is rotatably mounted on the bucket wheel axis and at which is fastened an annular carrier carrying the buckets. The supporting body is composed of a single supporting disc configured in the form of the envelope of a cone frustum. This configuration has the advantage of a very simple structure, with no welding work being necessary within a spatial body. Moreover, these bucket wheels have the additional advantages that no incompatibilities with respect to the shape exist at the connection between wheel and shaft nor any sudden changes in rigidity. Additionally, no or hardly any surfaces exist which would permit the attachment of dirt. Since it is not possible to manufacture the supporting bodies of one piece in dependence on the diameter of the bucket wheels, segments must be produced here which lead to problems with structural tolerances when later welded together. The additional danger exists that the disc composed of a relatively thin metal sheet is deformed during welding and must thus be put on the scrap heap. However, alternative manufacturing processes such as, for example, deep drawing of a metal sheet, are able to overcome these drawbacks.
German examined published patent application DE-AS 1,073,402 discloses a bucket wheel for excavators. The hub supported on the bucket wheel axis by two bearing locations has a conical configuration and its tapered end is disposed on the side of the bucket wheel facing away from the discharge side. Moreover, the discharge chutes are connected to the broadened end of the hub and are connected with the tapered end of the hub by supporting struts. The ring carrying the buckets is connected with the hub by spokes that do not extend radially to the bucket wheel axis; they preferably extend tangentially to the tapered end of the hub. This embodiment, which is known as a spoke wheel, has the drawback that it requires a relatively large amount of welding work in the region of the inner and outer circumference of the bucket wheel. Moreover, the danger exists here that dirt is able to accumulate relatively quickly in the free spaces between the spokes and thus jeopardizes the proper operation of the bucket wheel. Although it is easy to see the dirt in view of the open configuration, it is relatively expensive to remove it.
German unexamined published patent application DE-OS 2,609,965 discloses a bucket wheel for loading or manipulating bulk materials. The bucket wheel is equipped with compartments (cells) for emptying the bulk material, with partitions in the housing structure forming the compartments for the buckets. At least some of the compartments are open at the edge of the housing structure to receive material to be conveyed from the buckets. The compartments extend diagonally inwardly from the edge of the housing structure in a direction opposite to the direction of rotation of the bucket wheel. The compartments are provided with deflecting surfaces that slope radially inwardly and at an angle in the direction of rotation of the bucket wheel from one side face of the housing structure toward a discharge edge of extended length in the second-side face of the housing structure. This relatively complicated structural embodiment, also known as a cellular wheel, is relatively heavy, on the one hand, and, on the other hand, has the drawback that numerous metal sheets and reinforcements must be provided at the side walls of the bucket wheel. The bucket wheel is composed of a plurality of chambers, with the weld seams being absolutely inaccessible. Large areas are formed where dirt is able to collect. Here again two bearing locations are required to support the complicated structure. Particularly in connection with stockpile clearing devices (bucket wheels), the advantage exists that the sloped cell faces which extend radially inwardly are amenable to the flow of material and thus the inwardly successive material intake location (conveyor belt) is protected if heavy chunks come in.
The prior art bucket wheels in use thus include the so-called non-cellular bucket wheels, spoke wheels and cellular bucket wheels, with the robust cellular wheels also being usable for difficult applications.